feat(reject-history): multi-pareto 3×2 grid with cross-filter linkage

Replace single-dimension Pareto dropdown with 6 simultaneous Pareto charts
(不良原因, PACKAGE, TYPE, WORKFLOW, 站點, 機台) in a responsive 3-column grid.
Clicking items in one Pareto cross-filters the other 5 (exclude-self logic),
and the detail table applies all dimension selections with AND logic.

Backend:
- Add batch-pareto endpoint (cache-only, no Oracle queries)
- Add _apply_cross_filter() with exclude-self pattern
- Extend view/export endpoints for multi-dimension sel_* params

Frontend:
- New ParetoGrid.vue wrapping 6 ParetoSection instances
- Simplify ParetoSection: remove dimension dropdown, keep TOP20 toggle
- Replace single-dimension state with paretoSelections reactive object
- Adaptive x-axis labels (font size, rotation, hideOverlap) for compact grid
- Responsive grid: 3-col desktop, 2-col tablet, 1-col mobile

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

frontend/tests/report-filter-strategy.test.js

@@ -3,6 +3,7 @@ import assert from 'node:assert/strict';
 
 import {
   buildRejectOptionsRequestParams,
+  buildViewParams,
   pruneRejectFilterSelections,
 } from '../src/core/reject-history-filters.js';
 import {
@@ -62,6 +63,45 @@ test('reject-history prune removes invalid selected values', () => {
   assert.equal(pruned.removedCount, 3);
 });
 
+test('reject-history view params include multi-dimension pareto selections', () => {
+  const params = buildViewParams('qid-001', {
+    supplementaryFilters: {
+      packages: ['PKG-A'],
+      workcenterGroups: ['WB'],
+      reason: '001_A',
+    },
+    trendDates: ['2026-02-01'],
+    paretoSelections: {
+      reason: ['001_A'],
+      type: ['TYPE-A', 'TYPE-B'],
+      workflow: ['WF-01'],
+    },
+    page: 2,
+    perPage: 80,
+    policyFilters: {
+      includeExcludedScrap: true,
+      excludeMaterialScrap: false,
+      excludePbDiode: false,
+    },
+  });
+
+  assert.deepEqual(params, {
+    query_id: 'qid-001',
+    packages: ['PKG-A'],
+    workcenter_groups: ['WB'],
+    reason: '001_A',
+    trend_dates: ['2026-02-01'],
+    sel_reason: ['001_A'],
+    sel_type: ['TYPE-A', 'TYPE-B'],
+    sel_workflow: ['WF-01'],
+    page: 2,
+    per_page: 80,
+    include_excluded_scrap: 'true',
+    exclude_material_scrap: 'false',
+    exclude_pb_diode: 'false',
+  });
+});
+
 test('resource-history derives families from upstream group and flags', () => {
   const resources = [
     { id: 'R1', name: 'MC-01', family: 'FAM-A', workcenterGroup: 'WB', isProduction: true, isKey: true, isMonitor: false },